text: Let us assume that a particle supports only electric and magnetic dipole modes with polarizabilities  and  (here we use the notation of magnetic polarizability in the manner of Bekshaev et al. rather than the notation of Nieto-Vesperinas et al.) expressed through the Mie coefficients as 
  Then the cross sections are given by   and 
  For the case of a no-inside-gain particle, i.e. no energy is emitted by the particle internally (), we have a particular case of the Optical theorem <math display="block">
  \frac{1}{4\pi \varepsilon \varepsilon_0} \Im(\alpha^e) + \frac{1}{4\pi \mu \mu_0} \Im(\alpha^m) \geq \frac{2 k^3}{3} \left[ \frac{|\alpha^e|^2}{(4\pi \varepsilon \varepsilon_0)^2}  + \frac{|\alpha^m|^2}{(4\pi \mu \mu_0)^2} \right]